Diseases of the animal urinary tract have prevailed in recent years among many pets such as dogs and cats, and the incidence of such diseases is now increasing. Major causes of such diseases have been believed to be physical discomfort due to lack of exercise because many of pets are kept indoors by a recent change of urbanized human living environment, and in that the ready-made foods sold for pets are limited in kinds and are biased in nutrition. However, these are mere suppositions. The true causes of animal urinary tract diseases have not been determined as yet.
In veterinary medicine, it is required to counteract the expansion of the diseases of the animal urinary tract with a simple diagnostic method of such diseases by external observation. However, at this time there is no externally observable simple diagnostic test available, because there has not been found any practical reagent and means which are useful to detect diseases of the animal urinary tract. There was some speculation that an alkaline urine is indicative of such a disease, however, it has been proven that the relationship does not always exist between the alkaline urine and such diseases because phosphorus ions or the like from the pet food strongly affect the urine.
Metal ions in the urine can also be determined by enzymolysis. However, this method is not practical because it requires a relatively expensive reagent prepared by a complicated process. It has inferior shelf life (about one month even when preserved in a refrigerator), and it has a low reactivity and reliability. The reagent is inconvenient to handle and a test solution of the reagent is clear so that a quantitative determination can be made only by absorptiometry and thus a simple diagnosis by external observation is impossible.